Wildlife populations are suffering death by a thousand cuts as a result of human activities. Wildlife is being hunted, fished and poached. They are suffering from climate change and pollution. Diseases take their toll, as do newly invasive species. They are also being fragmented as a function of increased habitat destruction.
These are obvious culprits of environmental disruption. But there is one realm where we may be having an unanticipated impact on wildlife: nature-based tourism.
It is possible that our increasing penchant for nature tourism is making wildlife in these areas more vulnerable to predators. Unfortunately, we don’t yet have enough data to properly assess this risk.
A study attempts to understand how animals may become more docile, bolder and less fearful when exposed to humans. Researchers suggest this could then potentially lead to an increased risk of predation when people leave the area, signalling an unrecognised cost of eco-tourism.
A ‘human shield’
To domesticate animals, we must tame them and this often means deliberately selecting those individuals that are more docile and tolerant. Domestication is, in part, achieved by making animals safe from predators – for example by fencing them in, bringing them into our homes or raising them in cages.
We are now learning that urbanisation causes similar effects: animals that prosper in the cities are generally more docile and less fearful of humans than animals that live outside the cities.
In many cases, predators avoid urban areas, creating a “human shield” that protects urban prey and can trigger a cascade of ecological changes.
But urbanised areas are not the only context where human shields can arise. Nature-based tourism, too, might create a shield effect.
More tourists, more animals getting eaten?
According to a recent report, there are more than eight billion visits to terrestrial protected areas annually. That’s as if each person on Earth visited a protected area once, and then some! This number is even more impressive given that the report only considered visitors to protected areas larger than 10 hectares and didn’t include marine protected areas.
Such a human presence on natural areas has obvious damaging effects such as increased traffic and pollution, vegetation trampling and vehicle collisions with wildlife. However, a study speculates that nature-based tourism might, under certain circumstances, also create a human shield that makes wildlife more vulnerable to predators.
We already know that this has increased some species’ vulnerability to wildlife poachers and illegal hunters. There is some evidence that animals that are bold around humans may also be bold around their predators. For instance, fox squirrels from a population habituated to human presence responded less to different predator noises than individuals from the non-habituated population.
So if tourism-related human shields are sufficiently stable to make animals more tolerant towards humans and if by being exposed to humans, animals become more docile or excessively bold, these individuals may be more vulnerable when exposed to real predators.
